Add documentation for building container images

Signed-off-by: Helder Correia <174525+helderco@users.noreply.github.com>

docs/core-concepts/1205-container-images.md

@@ -4,3 +4,41 @@ displayed_sidebar: europa
 ---
 
 # Building container images
+
+You can use Dagger to build container images. Here's a simple example of a [Dockerfile](https://docs.docker.com/develop/develop-images/dockerfile_best-practices/) build:
+
+```cue file=../tests/core-concepts/container-images/plans/with-dockerfile.cue
+```
+
+## Building with CUE
+
+`Dockerfile` files are easy to start, but you can also build images entirely in CUE. The following example produces the same image as above:
+
+```cue file=../tests/core-concepts/container-images/plans/build.cue
+```
+
+## Automation
+
+Building images in CUE gives you greater flexibility. For example, you can automate building multiple versions of an image, and deploy, all in Dagger:
+
+```cue file=../tests/core-concepts/container-images/plans/template.cue
+```
+
+Now you can deploy all versions:
+
+```shell
+dagger do versions
+```
+
+Or just build a specific version, without pushing:
+
+```shell
+dagger do versions 8.0 build
+```
+
+## Multi-stage build
+
+Another common pattern is [multi-stage builds](https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds). This allows you to have heavier build images during the build process, and copy the built artifacts into a cleaner and lighter image to run in production.
+
+```cue file=../tests/core-concepts/container-images/plans/multi-stage.cue
+```